It’s impossible to deny that the culture of uploading and downloading 3D printable files—free or for profit—has been one of the most exciting aspects of the consumer 3D printing revolution. A quick search of the internet’s many 3D model platforms reveals a multitude of weird and wonderful creations, both fun and functional.

But just like in the entertainment industry, the 3D printing industry is facing a problem of copyright violation. Bootlegging has long been a problem faced by both music and film distributors, and a similar phenomenon is now taking place in the additive world.

The problem is that, as soon as your carefully crafted STL is on someone else’s hard drive, that downloader can rename the file, re-upload it, and even profit from it.

Watermark 3D aims to tackle this problem by embedding hidden watermarks onto 3D files, meaning creators can detect if a file has been illegally re-uploaded.

The watermark can only be detected by uploading the STL file to the Watermark 3D website, and entering the user-created password. If the password is correct, the watermark can be detected, revealing the owner of the IP.

The system allows creators to apply different watermarks to files given to different customers, which makes it easy to detect which individual customer has illegally re-uploaded the file.

Treatstock is also working on a more advanced tracking system that will notify the creator whenever their watermarked file appears online, and where.

It all sounds rather rosy, but the watermarking system may not be entirely watertight…yet.

One obvious limitation of the service concerns models that have already been 3D printed. Since the watermark is entirely digital and requires the upload of an STL file, 3D printed iterations of an STL file are not in any way watermarked.

This means bootleggers can download an STL file and sell 3D prints of that model for personal profit.

A more serious problem, one that undermines even digital files, has been pointed out by a YouTube commenter, who noted that remeshing the 3D model can remove the embedded watermark altogether.

Treatstock responded to this user by admitting to the problem, but pointing out that remeshing often involves a geometric reworking of a file, which “sometimes can be critical to the outcome of the finished product.”

Other complaints include the suggestion that users could simply download or purchase a file without a watermark—like most files on the web—before sticking their own watermark on it and claiming the file as their own. Somewhat confusingly, Watermark 3D also allows multiple, separate watermarks to be placed on a single file.

Despite having some big issues that need ironing out, Treatstock’s free service (which allows for 10 watermarks per day) might come as a relief to the many model creators whose works have been stolen by others.